Answer:
B. 
Step-by-step explanation:
Let n be the number.
We are asked to write an mathematical expression for the given word phrase.
One third of a number, n, would be
.
Two more than one third of a number, n, would be
.
We are told that Two more than one-third of a number is 8. We can represent this information in an equation as:

Therefore, option B is the correct choice.
Given that the<span> iq scores for large populations are centered at 100.
To get what percent of these 78 students have scores above 100 we conduct a normal distribution probability of the data.
P(x > 100) = P(z > (100 - 100)/sd) = P(z > 0) = 1 - P(z < 0) = 1 - 0.5 = 0.5 = 50%
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Answer:
(negative 7 x + 4)(negative 7 x minus 4)
Step-by-step explanation:
Consider two real numbers a and b. A difference of squares involving a and b is usually given as;

The difference of the two squares above can be factored to yield;

This implies that in order to have the difference of squares we must have a product involving the difference and the sum of the numbers.
The expression;
(negative 7 x + 4)(negative 7 x minus 4) can also be written as ( 4 - 7x) ( -4 - 7x)
( 4 - 7x) ( -4 - 7x) = ( 4 - 7x) (-1( 4 + 7x)) = -1 *( 4 - 7x) ( 4 + 7x)
Expanding the last expression yields;
-1 (16 + 28x -28x - 49x^2) = -1 (16 - 49x^2) = 49x^2 - 16 which is in deed a difference of squares